Grate-bar



(No Model.)

C. SMITH 8v J. HUTCHINSON.

GRATE BAR.

Patented Oct. 2, 1883.

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.UNITED STATES TTTCE.

PATENT G RATEHBA'R.

SPECIFICATION forming part of Letters Patent No. 286,053, dated October 2, 18%33` Application filed August 4, 1883. (No model.)

To all whom, t may concern:

Be it known that we, CHARLES SMITH and JOSEPH HUroHINsoN, of Chicago, county of Cook, and State of Illinois, have invented certain new and useful Improvements in Grate- Bars, of which the following is a full, clear, and exact description, that will enable others to make and use the same, reference being had to the accompanying drawings, forming a part of this specification.

This invention relates to improvements in grate-bars for smokeconsuming furnaces; and it consists of a hollow bar provided with a number of hollow lugs projecting upward from the upper surface of said bar, said lugs being perforated on the side next the fire for the purpose of discharging the heated air at a point above the level of the grate-bars.

Figure lis a longitudinal section of a boilerfurnace embodying our improved feature; Fig. 2, a transverse section, and Fig. 3 a view in perspective, of a portion of a boiler-furnace.

Referring to the drawings, A represents a boiler; B, the inclosing-walls; a, the boilerA front, a', the bridge-wall; C, the ash-pit, and D the combustion-chamber. One of the hollow bars E is placed at each side of the furnace, the intermediate grate-bars, F, being of the usual or any other pattern. The bars E may be so constructed as to take the air from the ash-pit through the under side or in at the side of the bar next the inclosingwalls through the air-passage b. The upper side of the bar E is provided with the upwardrprojecting hollow lugs d, which are perforated on the side next vthe fire, and through which the air is d-ischarged into the combustion-chamber. These lugs are of a rectangular form, and are arranged at regularintervals from the front end of the bar back to a point about one-third of its length.

It has been learned by practical experiments that the portion of air admitted through the side walls and hollow bars should be nearer the front end of the furnace, and for this reason the hollow bars are not provided with lugs or openings into the furnace beyond a certain point. The lugs projecting above the level of the grate-bars become very hot, so that the air in coming up from the hollow bars is heated to a high degree of temperature before it mingles with the other products of combustion in the furnace. i

This form of our device is readily and quickly placed in position for service, for where the furnace is already constructed all that is necessary is the removal of a grate-bar from each side of thefire-box, and then replacing the same with our improved bar adapted to take airin on the under side. Y

In constructing new furnaces, or in altering over old ones, when it is desired to take the atmospheric air through passages in the side walls, the hollow bars may be set into the wall, so as to take the air altogether from the side instead of the bottom of thefhollow bar.

The bridge-wall is built close up to the boiler, and is provided with the square opening d, through which the iiames escape from thecombustion-chamber. Y

Having thus described your invention, what we claim as new, and desire to secure by Letters Patent, is y l. A hollow grate-bar adapted to take air from the bottom or side next lthe inclosingwalls, and provided with a number of hollow. perforated lugs projecting upward from and arranged at regular intervals along a part of said bar, substantially as and for the purpose set forth. t

2. The combination, with an air-passage l0- cated in the side walls inclosing the furnace, of a hollow grate-bar placed against saidlwalls at each side of the furnace, and provided with hollow perforated lugs projecting from the upper surface of said bar, and discharging heated air into the/ furnace above the level of the grate-bars, substantially as and for the purpose set forth.

CHARLES SMITH. JOSEPH HUTCHINSON. VVitnesses:

L. M. FREEMAN, L. B. CoUrLAND. 

